Establishment and primary application of Chinese hamster ovary cell clustering method for determination of activity of pertussis toxin

Abstract

Objective To establish Chinese hamster ovary (CHO) cell clustering method for determination of activity of pertussis toxin (PT) and apply the established method to quality control in production process of acellular pertussis vaccine (APV).Methods PT standards diluted serially were mixed with CHO cells.Sensitivity of CHO cell clustering by induced PT was observed,and different influence factors on CHO cell clustering,including reaction time,pH value of reaction solution,buffer concentration and order of adding sample were studied.The established method was applied to PT activity detection before and after detoxification and residual PT activity in filamentous hemagglutinin and pertactin components in production process of APV.Results The optimal reaction time,pH value of reaction solution,buffer concentration and order of adding sample for the best CHO cell clustering by induced PT were 24 h,pH 7-8,0.15 mol/L,first adding CHO cells and then PT,respectively.Sensitivity of the established CHO cell clustering method was 10 pg/ml PT.This method had good repeatability.Conclusion The established CHO cell clustering method can be applied to PT activity detection. Key words: CHO cells; Pertussis toxin; Method